The present invention relates to an attachment assembly for the connection of ripper teeth to wheel or track-type tractors with ripper attachments. More particularly, the invention comprises a novel protective wear cap and ripper shank for reducing the drag of the ripper shank through the ground during use and protecting the shank from wear.
In soil excavation, it is common practice to loosen the soil so that it can be more easily loaded onto a skip loader or carry-all for removal. This is typically accomplished by dragging a plurality of ripper teeth through the soil by means of a wheel or track-type tractor. The tractor is provided with a hydraulically actuated box to which the ripper teeth are secured by means of a corresponding plurality of substantially "J"-shaped adaptors commonly known as ripper shanks. The individual ripper teeth are secured to the lower forward ends of the shanks by means of flex or roll pins. The shanks are in turn secured to the box on the tractor by a wedge key or suitable locking pin. While such a configuration is widely used, it has been found to have certain drawbacks. The forward surface of the ripper shanks, which is flat, creates additional drag for the tractor and is subjected to substantial wear during use, particularly in the area of the shank proximate to the tooth which is dragged through the ground with the tooth. As the shank wears, it becomes susceptible to breakage, requiring replacement.
Because of the costs associated with replacing the larger ripper shanks, wear caps have been developed in an effort to protect the lower portion of the shanks proximate the ripper teeth. These wear caps are generally "U"-shaped in cross section so as to cover the front surfaces of the shanks and they extend about the sides of the ripper shanks where they are secured to the shanks. This configuration results in a widening of the shank which further inhibits their ability to pass through the ground. In addition, the attachment members which hold these wear caps in place are typically secured to the ripper shanks by means of a locking pin which passes through the upper portions of the shanks proximate the ripper box. As this portion of the ripper shank experiences the greatest stress during use, these mounting holes create stress points which have lead to fracturing of the shanks.
It would be highly desirable to provide a wear cap for ripper shanks which reduce the wear on the shanks without increasing the drag of the shanks through the ground and without weakening the shanks. It would also be highly desirable to provide such a protective wear cap which cooperates with the ripper tooth so as to reduce the drag normally associated with unprotected conventional shanks. The ripper shank and wear cap configurations of the present invention achieve these results.